Cord connector for telephone instruments



Dec. 24, 1946. E. s. M LARN 2,413,930

CORD CONNECTOR FOR TELEPHONE INSTRUMENTS Filed Dec. 11, 1942 3 Sheets-Sheet l INVENTOR. 15' R/VEST 6.7% lag/v E. s. MCLARN 2,413,030

Sheets-Sheet 2 Dec. 24, 1946,

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IH II Dec. 24, 1946. E. s. M LARN CORD CONNECTOR FOR TELEPHONE IN$TRUMENTS 3 Sheets-Sheet 3 Filed Dec. 11. 1942 Patented Dec. 24,1946

CORD CONNECTOR FOB TELEPHONE INSTRUMENTS Ernest S. McLarn, Manhas set, N. Y., assignor to International Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application December 11, 1942, Serial No. 468,605

8 Claims.

This invention relates to telephone handsets and more particularly to means for connecting a multi-conductor cord to the transmitter and receiver units of such handsets.

An object of the invention is to provide an inexpensive, simple and efficient means for connecting the so-called tip-less cordage to telephone handsets not especially designed for use with such cordage.

In my copending application Serial No. 438,774 filed April 13, 1942, patented Oct. 3, 1944, No. 2,359,570, there is disclosed a telephone handset provided with a so-called tip-less cord which is threaded in a channel formed in the handset shell and extending down the handle from the transmitter cavity to the receiver cavity. The transmitter and receiver capsules are provided with connectors formed with sharp prongs which pierce the cord and make electrical connection with the proper stranded conductors when the transmitter and receiver caps are screwed down. It will be appreciated that this construction necessitates the use of specially constructed transmitter and receiver capsules or elements. It is therefore, another object of the present invention to provide adapter devices which will permit the use of standard transmitter and receiver capsules not equipped with the pronged connectors in a handset of the kind employing a continuous tip-less cord extending between the transmitter and receiver cavities.

These and other objects and features of the invention will be clear from a reading of the following description in conjunction with the accompanying drawings in which:

Fig. 1 is a plan view of a handset with the transmitter and receiver caps removed and the handle broken away,

Fig. 2 is a partial section of the transmitter end on the line 2-2 of Fig. 1,

Fig. 3 is a partial section of the transmitter end taken on the line 3-3 of Fig. 1 but also showing the cap and the transmitter capsule,

Fig. 4 is a plan View of the molded transmitter insert,

' Fig. 5 is a partial section of the receiver end on the line 55 of Fig. 1,

Fig. 6 is a partial section of the receiver end taken on the line 6-6 of Fig. 1 but also showing the cap and the receiver capsule,

Fig. '7 is a plan view of the molded receiver insert.

Referring first to Figs. 1 to 4, the handset comprises a molded shell having cavities I, 2 at each end for accommodating the transmitter and receiver capsules 4 and 5 respectively. A channel is molded along the length of the handset to receive a multiconductor cord with spaced conductors in fiat arrangement, more specifically fiat three conductor cord 3 which lies at the bottom of each cavity I, 2 and passes through the handle. The rubber or plastic cover of the cord 3 is formed with a longitudinal ridge which fits into a corresponding groove in the channel and thus ensures that the cord is correctly positioned therein. The cavity I adapted to receive the transmitter capsule 4 has molded in its bottom two cylindrical depression 6, 1 into which fit corresponding depending projections 8, 9 in the lower surfaces of the adapter.

The adapter comprises a molded insert as illustrated in Figs. 2 to 4 and consists of an annular base It) formed with the depending projections or pegs 8, 9 and diametrically disposed holes ll, [2. The upper surface is provided with a pair of arcuate projections l3, M the function of which will be explained later. The center of the base In is formed with a rectilinear 7 hole l5 provided at each corner with narrow slots l6 for accommodating the side edges of the contact members ll, l8. On each side of the hole l5 the bottom of the base I!) is formed with a line of molded teeth l9 which register with the cord 3 when the adapter is inserted in the transmitter cavity I.

The contact members I7, I13 consist of hard, metal strips the ends of which are bent over at. a right-angle the depending edges being provid-- ed with a plurality of sharp prongs 20. The con tact members l1, 18 are fastened to the base H]? by metal eyelets 2|, 22 which are inserted in the: holes ll, I2 and their lower ends spun over against the lower surface of the base member ID. The eyelets 2i, 22 also secure to the base member 10. a pair of U-shaped springs 23, 23 the free arms of which extend upwards into the cavity I.

To assemble the transmitter end, the adapter is positioned in the base of the cavity l with the projections 8, 9 fitted into the holes 6 and T. The transmitter capsule 4 is then inserted in the cavity l and the cap 25 screwed on to the end of the handset shell. An annular projection 26 on the inside of the cap 25 engages the capsule 4 and the act of screwing on the cap 25 forces the lower part of the capsule 4 against the top of the arcuate projections l3, I4 on the adapter base I 0 and at the same time causes contact to be made between the spring 23 and the capsule case and between the other spring 24 and the center terminal 36. The adapter base I is pressed firmly towards its seating in the base of the cavity I and the sharp prongs 20 of the contact members l1, l8 are caused to pierce the insulation of the cord 3 and are driven into the stranded wires of the two outer conductors. At the same time the teeth l9 are clamped against the upper surface of the cord 3 on either side of the prongs 20 thus securing the cords against movement.

Referring now to Figs. 5 to '7 the construction of the receiver end is generally similar to that of the transmitter end. The adapter shown in Figs. 5 to '7 comprises a molded block I0 formed with depending pegs 8', 9' adapted to fit into holes 6, l in the base of the cavity 2, and upwardly projecting cheeks I3, I 4' adapted to be engaged by the receiver capsule 5 when the cap 25' is screwed home. The central hole I5 is slightly off-set from center so that the prongs 20' of the contact members l1, l8 are off-set and will pierce the centre conductor and one of the outer conductors of the cord 3. A pair of U- shaped contact springs 23, 24' and the contact members ll, [8' are fastened to the block III by screw 29, 30 which are screwed into the holes.

ll, I2.

In assembling the receiver end, the block [0 is positioned in the receiver end cavity 2 with the pegs 8, 9 which are of difierent diameters entering the holes 6, I also of different diameters to correspond with the peg characters, the receiver capsule 5 is then inserted and the cap 25' screwed. on, during which operation the capsule 5 engages the cheeks l3, [4' on the block I0 and forces the prongs 20 into the stranded wires of the centre and one outer conductor of the cord 3: at the same time electrical contact is made between the terminals 21, 28 on the receiver capsule and the springs 24' and 23' respectively.

It will be understood of course that the two pronged contact members at the receiver end might be arranged to effect contact with the two outer conductors respectively and thetwo pronged contact members at the transmitter end to make contact with the centre and an outer conductor depending upon the manner in which the conductors of the cord 3 are connected to the substation circuit. In this arrangement, the pegs 8', 9' of the receiver capsule adapter and their corresponding holes 6, 1' need not be dissimilar in diameters a poling would not be necessary, whereas the pegs 8, 9, of the transmitter capsule adapter and their corresponding holes 6, 1' would be of different diameters to ensure of the pronged contact members piercing the proper conductors.

What I claim is:

1. A telephone transducer comprising a supporting shell, a transducer element, a cavity in said shell for accommodating said transducer element, a cover for the cavity, a conductor cord comprising a plurality of parallel conductors, means for positioning said cord at the bottom of said cavity, a detachable connector block having mounted thereon connector members formed with sharp prongs and also having mounted thereon yielding contacts shapedpsoas to make contact with the electrode terminals of the transducer element when the latter is inserted in said cavity, electrical connections between said connector mmebers and said yielding contacts, and means including the cover for forcing the said prongs of said connector members into saidcord to automatigally make electrical contact between said electrode terminals, and said, conductors; when.

4 said transducer element is seated in said cavity and for holding the yielding contacts against the electrode terminals.

2. A telephone transducer comprising a supporting shell, a transducer element, a cavity in said shell for accommodating said transducer element, a conductor cord comprising a plurality of parallel conductors, a channel in the bottom of said cavity for said conductor cord, a detachable connector block having mounted thereon a pair of connector members formed with depending sharp prongs and also having mounted thereon a pair of upwardly-extending spring contacts, electrical connections between said connector members and said spring contacts, a surface on said connector block which abuts a portion of the casing of said transducer element when the latter is inserted in said cavity said connector members and said spring contacts being so shaped and positioned that when said transducer element is forced home in said cavity said prongs are forced into said cord to make electrical contact with conductors thereof and said spring contacts make contact with the electrode terminals of said transducer element.

3. A telephone transducer according to claim 2 in which said connector block is provided with a plurality of projecting portions and the bottom of said cavity is formed with corresponding depressions to receive said projecting portions.

4. A telephone transducer according to claim 2 in which a common fastening means is provided for securing each connector memberand its corresponding spring contact to said connector block.

5. A telephone transducer according to claim 2 in which the lower surface of said connector block is, provided on either side of said prongs with teeth which are clamped down upon said cord when said transducer elements is forced home in said cavity.

6. A telephone transducer comprising a supporting shell, a transducer element, a cavity in said shell for accommodating said transducer element, a conductor cord comprising a plurality of parallel conductors, means for positioning said cord at the bottom of said cavity, a detachable connector block having mounted thereon connector members formed with sharp prongs and also having mounted thereon yielding contacts shaped so as tomake contact with the electrode terminals of said transducer element when the latter is inserted into said cavity, electrical connections between said connector members and said yielding contacts, an abutting surface on said connector block which abuts a portion of the casing of said transducer element when the latter is inserted into said cavity, a peripheral lip on said transducer element, a seating for said lip on said supporting shell at the edge of said cavity, and a threaded cap formed with an abutment which when said cap is screwed onto said shell forces said lip against said seating, the distance from the points of said prongs to said abutting surface on said connector block being such that when said lip is forced against its seating by the act of screwing on said cap, the said prongs are forced into said cord and make electrical contact with conductors-of said cord.

'7. A- telephone transducer comprising a supporting shell, a transducer element, a cavity in said shell. for accommodating said transducer element, a conductor cord comprising a plurality of parallel conductors, means for positioning said cord at the bottom of said cavity, a detachable connector. block. having mounted thereon connector member formed with sharp prongs and also having mounted thereon yielding contacts shaped so as to make contact with the electrode terminals of said transducer element when the latter is inserted into said cavity, electrical connections between said connector members and said yielding contacts, an abutting surface on said connector block which abuts a portion of the casing of said transducer element when the latter is inserted into said cavity, and a threaded cap formed with an abutment which when said cap is screwed onto said shell forces said transducer element and said connector block downwardly in said cavity, the distance from the points of said prongs to said abutting surface on said connector block being such that when said cap is in its screwed on position the said prongs are forced into said cord and make electrical contact with conductors of said cord.

A connector unit for insertion into a receptacle having at it bottom a multiconductor cord with spaced apart conductors and inwardlyextending guides at opposite sides of said cord,

a seat for a transducer element and a cap to 

